U.S. President Donald Trump took aim at Cuba and Venezuela at an event marking Hispanic heritage month at the White House on Friday.

The U.S. will not lift sanctions on Cuba "until it delivers full political freedom for the Cuban people," Trump said, reiterating a promise he made in the Florida's Little Havana community earlier in the year.

The Trump administration on Tuesday expelled 15 Cuban diplomats to protest Cuba's failure to protect staff at the U.S. embassy in Havana from a mysterious spate of health "attacks," spurring new tensions between the former Cold War foes.

The action delivers another blow to his Democratic predecessor Barack Obama's policy of rapprochement, including actions likely to erode the normalization of a relationship dominated for decades by mutual hostility and suspicion.